(±)14(15)eet

(±)14(15)-EET is a metabolite of arachidonic acid that is formed via epoxidation of arachidonic acid by cytochrome P450.[1],[2] It prevents increases in leukotriene B4, ICAM-1, and chemokine (C-C motif) ligand 1 (CCL2) induced by oxidized LDL in primary rat pulmonary artery endothelial cells (RPAECs) when used at a concentration of 1 μM.[3] (±)14(15)-EET induces dilation of preconstricted isolated canine coronary arterioles (EC50 = 0.2 pM).[4] It reduces myocardial infarct size as a percentage of the area at risk in a canine model of ischemia-reperfusion injury induced by left anterior descending coronary artery (LAD) occlusion when administered at a dose of 0.128 mg kg prior to occlusion or reperfusion.[5] Reference:[1]. Chacos, N., Falck, J.R., Wixtrom, C., et al. Novel epoxides formed during the liver cytochrome P-450 oxidation of arachidonic acid. Biochem. Biophys. Res. Commun. 104(3), 916-922 (1982).[2]. Oliw, E.H., Guengerich, F.P., and Oates, J.A. Oxygenation of arachidonic acid by hepatic monooxygenases. Isolation and metabolism of four epoxide intermediates. J. Biol. Chem. 257(7), 3771-3781 (1982).[3]. Jiang, J.-X., Zhang, S.-J., Xiong, Y.-K., et al. EETs attenuate ox-LDL-induced LTB4 production and activity by inhibiting p38 MAPK phosphorylation and 5-LO BLT1 receptor expression in rat pulmonary arterial endothelial cells. PLoS One 10(6), e0128278 (2015).[4]. Oltman, C.L., Weintraub, N.L., VanRollins, M., et al. Epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids are potent vasodilators in the canine coronary microcirculation. Circ. Res. 83(9), 932-939 (1998).[5]. Nithipatikom, K., Moore, J.M., Isbell, M.A., et al. Epoxyeicosatrienoic acids in cardioprotection: Ischemic versus reperfusion injury. Am. J. Physiol. Heart Circ. Physiol. 291(2), H537-H542 (2006).

Arachidonic acid is metabolized in the vascular endothelium to epoxytrienoic acids (EETs or EpETrEs) by cytochrome P450 enzymes. The EETs are released in response to acetylcholine, bradykinin, arachidonic acid, or cyclic stretch. (±)14(15)-EET-SI is the methyl sulfonamide analog of 14(15)-EET. This substitution results in a metabolically more stable compound because it is not sensitive to β-oxidation or membrane esterification. (±)14(15)-EET-SI is equipotent to 14(15)-EET in vascular agonist activity as measured by relaxation of precontracted bovine coronary arteries. In addition, 14(15)-EET and the methyl sulfonamide analog both stimulate tyrosine phosphorylation and induce mitogenesis in renal epithelial cells.

Epoxyeicosatrienoic acids (EETs), such as 11(12)-EET and 14(15)-EET, are cytochrome P450 metabolites of arachidonic acid that have been identified as endothelium-derived hyperpolarizing factors with vasodilator activity. 14,15-EE-5(Z)-E is a structural analog of 14,15-epoxyeicosatrienoic acids (14,15-EET) that antagonizes EET-induced relaxation of vascular smooth muscle. Relaxation of U46619-constricted bovine arteries by 14,15-EET could be inhibited approximately 80% by 14,15-EE-5(Z)-E at a concentration of 10 μM. 14,15-EE-5(Z)-E does not appear to antagonize nitric oxide- or iloprost-mediated vascular relaxation.

Epoxyeicosatrienoic acids (EETs), such as 11(12)-EET and 14(15)-EET, are cytochrome P450 metabolites of arachidonic acid that have been identified as endothelium-derived hyperpolarizing factors with vasodilator activity. 14,15-EE-8(Z)-E is a structural analog of 14(15)-EET that demonstrates potent vasodilator agonist activity in bovine coronary arteries similar to that of 14(15)-EET.

14S(15R)-EET is an oxylipin and a cytochrome P450 metabolite of arachidonic acid .114S(15R)-EET binds to isolated guinea pig monocytes with a Kivalue of 612.5 nM in a competitive binding assay using [3H]14(15)-EET.2It induces dilation of precontracted isolated canine epicardial arterioles (EC50= 4 pM) and denuded porcine subepicardial arterioles (EC50= 3 pM).3Unlike 14R(15S)-EET, 14S(15R)-EET does not inhibit COX in enzyme assays or isolated platelets.4 1.Daikh, B.E., Lasker, J.M., Raucy, J.L., et al.Regio- and stereoselective epoxidation of arachidonic acid by human cytochromes P450 2C8 and 2C91J. Pharmacol. Exp. Ther.271(3)1427-1433(1994) 2.Wong, P.Y.-K., Lai, P.-S., and Falck, J.R.Mechanism and signal transduction of 14 (R), 15 (S)-epoxyeicosatrienoic acid (14,15-EET) binding in guinea pig monocytesProstaglandins Other Lipid Mediat.62(4)321-333(2000) 3.Zhang, Y., Oltman, C.L., Lu, T., et al.EET homologs potently dilate coronary microvessels and activate BKCa channelsAm. J. Physiol. Heart Circ. Physiol.280(6)H2430-H2440(2001) 4.Fitzpatrick, F.A., Ennis, M.D., Baze, M.E., et al.Inhibition of cyclooxygenase activity and platelet aggregation by epoxyeicosatrienoic acidsJ. Biol. Chem.261(2)15334-15338(1986)

CAY10770 is an inhibitor of the cytochrome P450 (CYP) isoform CYP4Z1 (IC50= 5.9 μM).1It is selective for CYP4Z1 over CYP4A11, CYP4F2, CYP4F3a, CYP4F3b (IC50s = 187-282 μM) but does inhibit CYP4F8 and CYP4F12 (IC50s = 167 and 91 μM, respectively). CAY10770 (3 μM) inhibits the production of 14(15)-EET, 19-HETE, and 14(15)-DiHET by 83, 86, and 80%, respectively, in T47D breast cancer cells expressing CYP4Z1. 1.Kowalski, J.P., McDonald, M.G., Pelletier, R.D., et al.Design and characterization of the first selective and potent mechanism-based inhibitor of cytochrome P450 4Z1J. Med. Chem.63(9)4824-4836(2020)

EDHF (endothelium-derived hyperpolarizing factor) is an unidentified mediator released from vascular endothelial cells in response to acetylcholine and bradykinin which is distinct from the NOS- (nitric oxide) and COX-derived (prostacyclin) vasodilators.[1],[2]Cytochrome P450 (CYP450) metabolism of polyunsaturated fatty acids produces epoxides such as (±)14(15)-EET which are prime candidates for the actual active mediator.[3] However, the CYP450 metabolites of eicosapentaenoic acid and docosahexaenoic acid have been little studied relative to arachidonate epoxygenase metabolites. (±)16(17)-EpDPA is the DHA homolog of (±)14(15)-EpETrE, derived via epoxidation of the 16,17-double bond of DHA. The EDHF activity of (±)16(17)-EpDPA has not yet been determined. The epoxygenase metabolites of DHA have also been detected in a mouse inflammation model.[4]

14S(15R)-EET methyl ester, an oxylipin derived from arachidonic acid through cytochrome P450 metabolism, demonstrates specific biological activities. It exhibits affinity for isolated guinea pig monocytes, evidenced by a competitive binding assay with a Ki value of 612.5 nM using [3H]14(15)-EET. This compound notably enhances the dilation of precontracted isolated canine epicardial arterioles (EC50= 4 pM) and denuded porcine subepicardial arterioles (EC50= 3 pM), indicating potent vasodilatory effects. Unlike its isomer 14R(15S)-EET, 14S(15R)-EET methyl ester does not inhibit COX activity in enzyme assays or affect isolated platelets, highlighting its distinct functional profile.